This invention relates to systems for containing and dispensing fluids and is particularly concerned with portable containers for fluid used in servicing aircraft, e.g., hydraulic fluids and engine oil.
Portable containers for hydraulic fluids or engine oil, which may be of 5-gallon, 25-gallon, or even 55-gallon size, are typically filled from either 55-gallon drums or "totes," which are stationary 260-360-gallon containers mounted on a pallet,
Five-gallon containers filled with fluid are commonly either mounted on or integral with carts and wheeled to an airplane for routine servicing, where they dispense hydraulic fluid or engine oil via a hand pump to the specific aircraft systems using such fluids. These containers may be made of stainless steel or durable polymers, a preferred container of the latter type being described and claimed in applicant's concurrently filed patent application Ser. No. 08/236,199, filed on May 2, 1994, now U.S. Pat No. 5,494,191.
When an airplane is to be reconditioned after a predetermined number of hours of service, the various fluids are completely drained and replaced. Heretofore, large 55-gallon metal containers, permanently mounted on a lift truck, have been driven to the aircraft, typically located in a hangar, where current from the truck battery was used to drive a pump that dispensed fluid (especially engine oil) from the container to the appropriate system on the aircraft. This container is subject to contamination with both dirt and water, condensation often occurring in the container during humid weather. Both dirt and water cause serious damage to the hydraulic and lubricating systems on aircraft, dirt for obvious reasons and water because of reaction with the phosphate esters in synthetic fluids to yield a highly acidic and corrosive product. Further, because of the unitary construction, damage to the container has required removing both the container and the truck from service. At least one airline has also used a 25-gallon cylindrical plastic container, protectively surrounded by a metal shell on which various fittings, meters, etc., were installed, as a portable unit from which fluids were dispensed. This unit has been carried by both lift trucks and pickup trucks, electrical power being supplied from the truck battery to a pump for dispensing the fluid. The metal shell adds weight, and this unit is also susceptible to contamination by particulate matter and water.